[layer8]

> Now that I am close to sixty, this is a really big deal, and partly why I walk. It is the least injury-prone exercise.

I’d say biking is (in the right environment). It’s certainly easier on the knees than walking.

[Johnny555]

Though biking for older people is probably more risky in the event of a fall.

Also, walking is weight bearing exercise, which is supposed to be better for bone strength.